The present invention relates in general to combination locks, and more particularly to dial mechanisms for combination locks having a dial knob and associated dial back-up case with a digital readout display rather than the usual numerical indicia on a rotating dial member.
Heretofore, combination lock dial and dial ring assemblies for combination locks have customarily employed a unitary dial and dial knob member wherein the dial is of a disc like configuration, usually having a slightly tapered or conical indicia bearing face with graduation marks and numerals thereon, while the dial knob portion projects forwardly from the center thereof and is also usually in a truncated conical configuration providing a circular front end face and is usually provided ribs, serrations, knurled surface formations, or other friction increasing surface treatment of the conical surface of the unitary dial and knob member. The dial portion of the unitary dial and knob member customarily is received in a cylindrical well of only slightly larger diameter than the outer diameter of the dial portion formed in a dial ring or outer surround formation, sometimes referred to as an escutcheon plate, encircling the dial portion of the knob and dial member. Other combination lock dial and ring assemblies have taken the form of a shield or cover of tubular cylindrical configuration having an interruption providing a viewing window or opening, encircling a peripheral cylindrical flange surface of a cylindrical dial portion of a unitary dial and knob member, with the dial markings and numerals provided on the peripheral cylindrical flange surface of the dial portion. Thus the view opening or window forming interruption of the shield or cover of the dial ring exposes only a limited number of the dial markings to view, for the purpose of reducing the field or area in which the dial numbers can be observed while the operator knowing the combination is dialing the opening combination, thus limiting the range of exposed dial markings which are visible to unauthorized persons, and also to facilitate viewing of the dial markings by the authorized operator along a sight axis directed almost vertically downwardly. Examples of these last-described types of dial and ring assemblies may be found in U.S. Pat. No. 2,690,664 to Harry C. Miller and U.S. Pat. No. 4,197,726 to Uyeda.
It has been recognized for a number of years that one of the difficulties with conventional combination lock dial assemblies has been the problem of misdialing a combination lock by failing to rotate the dial and knob assembly through the proper number of turns in each direction through the proper dialing procedure for opening the lock. As is well known to persons skilled in the combination lock field, combination locks with the usual three tumbler wheel pack and driving cam mechanism most prevalent in combination locks require rotation of the combination lock through at least three complete revolutions in a first direction followed by alignment of the proper first combination number with the fixed index mark, then rotation of the dial through at least two complete revolutions in an opposite second direction to the alignment position for the next dial number with the index mark, followed by one complete revolution in the first direction to align the last of the three combination numbers with the index mark, and then the dial is rotated to a zero or opening position to effect interlinking of the fence lever, pivoted to the slidable bolt, with the peripheral gates in the tumbers and the driving cam gate to effect retraction of the bolt to open the lock. Frequently, misdialings occur because the operator fails to rotate the dial and knob assembly through the proper number of complete turns in one of the successive steps in the procedure, resulting in an accidental misdialing of the combination. Since many combination locks in very high security installations also frequently have devices associated therewith for producing alarms when the combination is misdialed or automatically achieving a lock-out of the lock when a misdialing occurs, this can present considerable time loss problems or require assistance of skilled locksmiths or security personnel to clear the combination lock for another proper dialing procedure.
Also, many misdialing errors occur where the combination lock is located in poor lighting conditions, particularly where limited sight openings or sight angles are incorporated in the dial system to limit unauthorized observation of dialing of the combination. Where alarm systems are incorporated in the combination lock system to generate alarms or lockouts when the combination is misdialed, this can also produce undesired time loss or occupation of security or highly skilled personnel.
An object of the present invention is the provision of a novel combination lock dial system, wherein a digital display of the combination number being dialed is presented by a light emitting source, such as light emitting diodes (LED's), permitting the operator to readily see the combination numbers being dialed in poor lighting conditions, or even in the dark.
Another object of the present invention is the provision of a novel illuminated electronic dial assembly for combination locks, providing a digital light generating readout displaying the numerals corresponding to the position of the dial in accordance with a usual combination lock dialing numerical system.
Another object of the present invention is the provision of a novel illuminated electronic dial assembly for combination locks, wherein a digital readout dial is provided which produces light source numerical displays of the numerals representing the dial angular position, and wherein the readout display does not light up until the dial has been advanced through the correct number of turns in the proper direction for the prescribed dialing procedure to open the lock.
Other objects, advantages and capabilities of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings illustrating a preferred embodiment of the invention.